A. Field of the Invention
The field of the present invention relates generally to liquid spray nozzles. More particularly, the present invention relates to liquid spray nozzles that are configured for use at the end of a conduit, such as a hose or pipe, for spraying liquid therefrom. Even more particularly the present invention relates to such nozzles that convert a stream of pressurized liquid into a relatively gentle spray comprising a plurality of uniformly sized droplets.
B. Background
The use of a spray nozzle at the end of a conduit, such as a hose or pipe, to convert a pressurized stream of liquid into a spray pattern has been well known for many years. Spray nozzles are commonly attached to the end of a garden or other type of hose to allow the user to convert the flowing stream into a spray pattern to more effectively distribute water over the surface on which the water is needed or desired. Spray nozzles are also commonly attached to the threaded end of a pipe or other conduit, which may be fixed in place, for use as a shower, car wash or other facility. The general objective of all such nozzles is to break up the linear stream of liquid into a spray pattern that covers more area with less pressure or impact on specific areas of the object being sprayed. For instance, when used to water lawns, gardens or turf, the use of a spray nozzle at the end of a hose has the advantage of covering the area being watered with a more gentle flow than would otherwise be obtained by merely directing the stream from the hose. As well known, without the spray nozzle, the pressurized stream of water from the hose would be concentrated in small areas that could dig or gouge out a portion of the area being watered. Although even mature vegetation could be harmed by direct application of the pressurized stream of liquid, such action would be particularly harmful for seeded or newly planted areas. It is well known that people, animals, automobiles, structures and most other objects also benefit from conversion of a pressurized stream of water to a spray pattern that prevents the stream being directed in a relatively small area of the object.
Nozzles configured for use at the end of a hose, commonly referred to as hose end nozzles, are typically provided in either a pistol-grip, barrel-type or shower head configuration. Generally, most such nozzles utilize a coupling mechanism or the like to attach to the threaded end of the hose. As the name implies, pistol-grip nozzles are typically configured with a tubular body in the shape of a pistol or like object with a handle that attaches to the hose and a trigger or lever apparatus that is squeezed to control the spray pattern and flow of water out the end of the barrel portion of the nozzle. Typically, the tighter the trigger is squeezed the more the spray pattern resembles a stream of water. The usual mechanism for controlling the spray pattern is a valve stem that is disposed in the barrel's flow channel and which moves in response to the trigger operation. Barrel-type nozzles typically have a somewhat cylindrically-shaped body that connects at one end to the hose and discharges water from an orifice at the opposite end of the body. Generally, a portion of the nozzle is retracted, extended or twisted by the user to adjust the flow rate and spray pattern of the fluid from the orifice. Shower head nozzles typically have a mechanism for attachment to the hose and an orifice/head portion that includes a plate having a plurality of small holes to separate the single, high volume stream of water into many small streams of water. Some of these types of nozzles utilize an orifice plate having a fixed number of specifically sized open holes, while others include a mechanism that allows the user to adjust the number and/or size of open holes.
A number of limitations are known to exist with the pistol-grip, barrel-type or shower head configured hose end nozzles. One such limitation common to these nozzles is that, in general, they are not well configured for certain uses, namely high volume, low to medium pressure uses such as watering golf courses and other turfs where the volume and pressure of the water is more likely to result in streams that can cause damage to the area being watered. Nozzles which are configured to avoid this problem can be somewhat cost prohibitive for the typical user. A limitation particularly applicable to the pistol or adjustable spray twist nozzles, which makes them somewhat unsuitable for use for plant watering or animal washing, is that as the valve stem is adjusted to create stream diffusion the flow rate is significantly reduced and the diameter of the spray becomes to large for effective watering or washing. The droplets may be of fairly uniform size, but they are very small and tend to drift in the wind, thereby welting the operator (i.e., a misting effect). A limitation particularly applicable to the shower head type of nozzle is that the velocity of each individual stream coming out of the nozzle is approximately the same as that of the original larger stream, which can have a significant negative effect on young or small plants as these small streams impact the plants. Perhaps the main disadvantage of the shower head type of nozzle that the small holes tend to plug if the water is not passed through a screen before reaching the nozzle. As well known, grass, sand or other debris commonly found in the water used for watering golf courses or other turf applications (which may be from reclaimed or other secondary water sources) or which contacts the nozzle from an external source (such as the ground), can somewhat significantly plug shower head nozzles. When a portion of the nozzle becomes plugged, the unplugged portion, such as the unplugged holes in a shower head nozzle, will have to pass the same total water volume as before, but at a higher pressure. As a result, the spray from the nozzle may have locally high pressure flow coming from the nozzle when it is not desired.
Other types of devices for liquid spray include nozzles having an out-of-round or irregularly shaped orifice and deflectors used to atomize the spray. Although the out-of-round or irregularly shaped nozzles do not have the plugging problems generally associated with the shower head nozzles, the droplet size of the spray is not uniform throughout the spray pattern. For instance, droplet size may be somewhat larger in the center of the stream or at the perimeter of the spray stream. As a result, some areas of the spray have a greater impact on the plant, animal or other spray object than other areas (or more than desired). Use of deflectors is a common method of atomizing large or small volume water streams into smaller droplets. The droplets are generally very small, resulting in wind drift (misting). In addition, the shape of the spray is generally not practical for hand watering of plants, washing of animals or other hand-held spray applications.
Improved spray/droplet formation and uniform droplet size are known to be important in many types of uses for improved watering or spraying. For instance, with regard to the watering of gardens, turf or other vegetative areas, breaking the pressurized stream of water into a plurality of uniformly sized droplets will provide a more gentle spray that will have less impact force on the plants and/or turf. Further, the more uniform spreading of the water spray will allow the water to penetrate the soil quicker and reduce the deleterious effects of water run-off, including damage to the soil, turf and vegetation and waste of water. In addition, breaking the pressurized stream of water into a plurality of uniformly sized, small droplets will provide greater and more effective area coverage for the same spray effort. Most conventionally configured spray nozzles, particularly hose end spray nozzles, do not provide or even attempt to provide uniform droplet sized spray. Some nozzles have incorporated one or more turbulence producing mechanisms, such as break-up pins or other devices that create turbulent flow inside the nozzle, to improve the formation of individual water droplets upon the spray exiting the nozzle and to achieve a lower pressure spray. These nozzles have generally not been successful with regard to creating a more uniformly distributed spray of uniformly sized droplets.
What is needed, therefore, is an improved liquid spray nozzle that is more effective at breaking up a pressurized stream of liquid flow into a plurality of uniform droplets at lower pressure to provide a more gentle spray. The preferred liquid spray nozzle should be configured to be adaptable for attachment to the end of a hose or other conduit and receive the full pressurized flow of the fluid therefrom. The preferred spray nozzle should be configured to resist plugging with debris, whether from the fluid or external sources, and not form a significant amount of mist. Ideally, the preferred spray nozzle should be relatively inexpensive to manufacture, easy to use and adaptable for a variety of different uses.